The naturally fractured rock in the open pit slope is susceptible to irreversible damage caused by fatigue loads related to freeze-thaw weathering, blasting vibration, earthquakes and tramcar traffic. To ensure the safety of rock mass and reveal how natural fracture affects the damage modelling characteristics is of great concern. Hence, this work aims at investigating the fatigue damage evolution of rock from volumetric deformation caused by F-T and cyclic loads. The rock structural deterioration and damage accumulation were investigated as well as the stimulated natural fracture pattern. Results show the frost heaving force acted on natural fracture results in the rock volumetric changes. The damage variable expressed by volumetric strain presents a linear relationship with freeze-thaw cycles. In addition, the axial, lateral and volumetric strain of marble exposed to cyclic loads present a two-stage pattern, they first increase quickly and then get to steady and last for a long time. A new fatigue damage model was established by considering the freeze-thaw damage and mechanical damage simultaneously. The proposed coupling damage model can well describe rock damage accumulation. Moreover, the CT images further reveal the influence of the natural fracture on rock volumetric deformation and the final damage accumulation. It is suggested that the opening-mode natural fractures contribute a lot to rock freeze-thaw deformation and fatigue deformation.

露天矿边坡中的天然破碎岩石容易受到与冻融风化、爆破振动、地震和有轨电车交通相关的疲劳载荷造成的不可逆损坏。确保岩体的安全并揭示天然裂缝如何影响损伤建模特征是非常值得关注的。因此，这项工作旨在研究由 FT 和循环载荷引起的体积变形引起的岩石疲劳损伤演变。研究了岩石结构退化和损伤积累以及受激天然裂缝模式。结果表明，冻胀力作用于天然裂缝导致岩石体积变化。以体积应变表示的损伤变量与冻融循环呈线性关系。此外，轴向、承受循环载荷的大理石的横向和体积应变呈现出两个阶段的模式，它们首先快速增加，然后稳定并持续很长时间。同时考虑冻融损伤和机械损伤，建立了一种新的疲劳损伤模型。提出的耦合损伤模型可以很好地描述岩石损伤累积。此外，CT图像进一步揭示了天然裂缝对岩石体积变形和最终损伤累积的影响。表明张开型天然裂缝对岩石冻融变形和疲劳变形的贡献很大。同时考虑冻融损伤和机械损伤，建立了一种新的疲劳损伤模型。提出的耦合损伤模型可以很好地描述岩石损伤累积。此外，CT图像进一步揭示了天然裂缝对岩石体积变形和最终损伤累积的影响。表明张开型天然裂缝对岩石冻融变形和疲劳变形的贡献很大。同时考虑冻融损伤和机械损伤，建立了一种新的疲劳损伤模型。提出的耦合损伤模型可以很好地描述岩石损伤累积。此外，CT图像进一步揭示了天然裂缝对岩石体积变形和最终损伤累积的影响。表明张开型天然裂缝对岩石冻融变形和疲劳变形的贡献很大。